Rock drill



Sept. 6, 1938. E.- G. GAR-rm 2,128,935

ROCK DRILL Fi led Aug. 20, 1934 Patented Sept. 6, 1938 PATENT GFFHCE ROCK DRILL Elmer G. Gartin, Claremont, N. H., assignor to Sullivan Machinery Company, a corporation of Massachusetts Application August 20,

' 18 Claims.

This invention relates to rock drills, and more particularly to improvements in the dri1l,steel chuck mechanisms of such drills.

An object of this invention is to provide an improved drill steel chuck mechanism for a rock drill. Another object is to provide an improved chuck mechanism for receiving and supporting a drill steel shank and having embodied therein improved means for locking the steel shank within the chuck. Yet another object is to provide an improved drill steel shank structure having improved driving and locking means. These. and other objects and advantages of the invention will, however, hereinafter more fully appear in the course of the following description and as more particularly pointed out in the appended claims. 7

In the accompanying drawing there are shown for purposes of illustration two forms which the E29 invention may assume in practice.

In this drawing-- Fig. 1 is a longitudinal sectional view through the forward portion of a rock drill within which one illustrative form of the improved chuck mechanism is embodied.

Fig. 2 is a cross sectional view taken on line 2--2 of Fig. 1.

Fig. 3 is a cross sectional view taken on line 33 of Fig. 1.

Fig. 4 is a cross sectional view taken on line 4-4 or Fig. 1.

Fig. 5 is a view similar to Fig. 1 showing a modified form of chuck mechanism.

Fig. 6 is a cross sectional view taken on line 6--6 of Fig. 5.

Fig. 7 is a cross sectional View taken on line 1-1 of Fig. 5.

Fig. 8 is a cross sectional view taken on line 8--8 of Fig. 5.

In the illustrative form of the invention shown in Figs. 1 to 4, inclusive, the improved chuck mechanism is embodied in a hammer rock drill comprising a cylinder l containing a reciprocable hammer piston having a forwardly pro- 4 jecting striking bar 2 adapted to deliver impact blows to the shank 3 of a rock drill steel 4 of improved design. As is usual in hammer rock drills of the character disclosed, the hammer piston partakes of rotary motion during its reciprocation, and this rotary motion is transmitted to the drill steel so that as the latter is percussively actuated it is at the same time rotated. As the particular means for effecting rotative and reciprocatory movements of the hammer piston does 1934, Serial No. 740,645

not enter into this invention, further description thereof is considered unnecessary.

Now referring to the improved chuck mechanism, it will be noted that the piston striking bar 2 has longitudinal grooves 5 interlocked with straight lugs 6 formed internally within a chuck sleeve I rotatably mounted in the bore 8 of a chuck housing 9. The chuck sleeve is formed, within its forward portion, with a bore if), and arranged within the rearward end of this bore, in abutting engagement with the forward ends of the lugs ii, is a wear bushing l I in the form of a hard metal ring for receiving and guiding the rearward portion of the drill steel t. Also arranged in the bore ii] of the chuck sleeve is a chuck bushing l2 for receiving and supporting the drill steel shank 3. In this instance, the drill steel is of polygonal cross section, herein in the form of a hexagon, and the steel shank is provided with a reduced cylindrical rear end 20 portion I3, guided in the wear bushing, and an intermediate reduced cylindrical portion M, the portion l5 of the hexagonal steel shank between the reduced portions l3 and M forming elongated steel driving means having relatively large wear- 2.5 ing surfaces; and this portion of the steel shank is loosely guided in. a hexagonal bore l6 formed in the chuck bushing l2, as shown in Fig. 4. The forward end of the chuck sleeve 7 is provided with clutch jaws II for receiving clutch teeth 58 9 formed on a front locking ring l9 arranged in the bore 8 on the chuck housing in advance of the chuck sleeve and chuck bushing and retained in the chuck housing bore by an inwardly directed lip 2Q formed on the forward end of the chuck housing, this lip encircling a central opening 2lthrough which the steel shank is inserted into driving and locking relation within the chuck mechanism. The clutch teeth IS on the locking ring l9 are also interlocked with chuck jaws 22, 22 formed within the forward end of the chuck bushing l2, these chuck jaws being formed by slots elongated laterally to permit a predetermined amount of rotary movement of the chuck bushing I2 with respect to the chuck sleeve. The locking ring I9 is provided with a central key opening 23 of hexagonal cross section for receiving the hexagonal drive portion l5 of the steel shank. When it is desired to insert the steel shank within the chuck mechanism, 50 the hexagonal drive portion l5 of the steel shank is inserted through the key opening 23 and then shoved rearwardly into the position shown in Fig. 1, the bore It in the chuck bushing at that time being in registry with the key opening 23. When the steel shank is thus disposed, the operator grasps the steel body and rotates the steel, together therewith the chuck bushing E2, into the position shown in Fig. 3, with the hexagonal driving portion i5 of the shank out of registry with the key opening 23 at that time, and as a result the steel shank is locked within its'chuck. Vfhen the steel shank is rotated into its locked position the ends of the elongated jaws 22 on the chuck bushing engage the inwardly projecting ends of the clutch teeth i8 on the locking ring,

and as the hammer piston is rotated the rotary motion thereof is transmitted through the grooves 5 on the striking bar, the straight lugs 6 on the chuck sleeve '5, and the chuck bushing l2 interlocked with the chuck sleeve by the clutch jaws on the locking ring to the drill steel, and the drill steel shank is retained in the chuck during percussive actuation thereof by the hamrner piston by the corners of the driving lug l5 engaging the inner walls of the flats of the key opening 23. When it is desired to release the steel shank from the chuck the steel shank and chuck bushing I2 are rotated to bring the hexagonal portion of the shank into registry with the key opening 23, and the steel is then axially withdrawn from its chuck through the key openmg.

In the modified form of the invention shown in Figs. 5 to 8, inclusive, the hammer motor with which the chuck mechanism is associated is generally the same as that described above. In this instance, the piston Striking bar 2 has straight grooves 55 interlocked with straight lugs 30 formed internally within a chuck sleeve 38 rotatably mounted in the bore 8 of the chuck housing 9. Arranged within the forward portion of the chuck sleeve 34 is a chuck bushing 32, the latter being interlocked with the chuck sleeve by keys 33 on the chuck bushing engaging longitudinal keyways 34 formed internally within the chuck sleeve. These keyways 34 are laterally elongated or widened to permit a predetermined rotative movement of the chuck bushing 32 with respect to the chuck sleeve 3|. In this instance, the forward end of the chuck sleeve is provided with chuck jaws 35 with which are interlocked clutch teeth 36 formed on a locking ring 37. Received in and supported by the chuck bushing 32 is the shank 38 of a drill steel 39 of an improved design, and the chuck bushing 32 is provided with a square opening 45 for receiving the elongated squared driving portion 41 of the steel shank. Formed in longitudinally spaced relation with respect to the squared portion 4! of the steel shank is a collar 42, while the steel shank between this collar and the portion 4! is of reduced cylindrical cross section at 43. The locking ring 3'1. is provided with a square key opening 44. When it is desired to insert the drill steel shank within the chuck mechanism, the squared portionr4l of the sleeve shank is inserted through the square key opening 44 and the shank shoved rearwardly within the registering opening 40 in the chuck bushing 32, and when the steel shank is in the position shown in Fig. 5, the operator grasps the steel body and rotates the steel shank and chuck bushing 32 relative to the chuck sleeve 3| into the position shown 'in Fig. 7, thereby locking the squared portion M of the steel shank out of registry, as shown in Fig. 8, with respect to the key opening 44. When the steel is thus locked in position, it is percussively actuated by the hammer piston and the rotary motion of the piston is transmitted to the steel through the straight grooves 5 on the striking bar, the straight lugs 30 on the chuck sleeve 3|, and the chuck bushing 32; the driving portion 4! of the steel shank being driven by the chuck sleeve 3! through the keys 33 on the chuck bushing engaging the end walls of the elongated keyways slots. When it is desired to release the drill shank from the chuck, the shank is rotated into a position wherein the squared driving portion 4! is in registry with the key opening 44, and the steel shank is then withdrawn axially through the key opening.

'As a result of this invention, it will be noted that an improved chuck mechanism is provided for driving and supporting a drill steel shank and having embodied therein improved means for locking the steel shank within the chuck. It will further be evident that an improved drill shank structure is provided with an elongated driving portion having relatively large wearing surfaces. These and other uses and advantages of the invention will be clearly apparent to those skilled in the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a rock drill chuck mechanism, the combination with a drill steel having a shank provided with an end portion of reduced cross section and an intermediate portion of reduced cross section, said reduced portions bracketing an elongated driving portion of greater cross section than said reduced portions and having relatively wide elongated wearing surfaces, a rotatable chuck for receiving the drill steel shank and having driving means provided with wide elongated driving surfaces engaging the wearing surfaces of said enlarged shank portion for rotating the drill steel, means supported by said chuck and engaging said reduced end portion for centering and guiding the steel shank, and means rotatable with said chuck and cooperating with said intermediate reduced portion for locking the drill steel shank within said chuck, said enlarged driving portion cooperating with said centering and guiding means for limiting inward movement of the steel shank within said chuck.

2. In a drill steel chuck mechanism, the combination of a drill steel having a shank provided with an elongated driving portion, a collar spaced therefrom, and a portion of reduced cross section connecting said collar with said driving portion, a rotatable chuck for receiving the drill steel shank and having driving means provided with wide elongated driving surfaces engaging said elongated driving portion, and means rotatable 'with said chuck and cooperating with said shank portion of reduced cross section for locking the cross sectional area than the steelportion forwardly thereof, said portions of reduced cross section bracketing the polygonal portion of the shank therebetween and said polygonal portion of theshank forming an elongated driving portion presenting relatively wide elongated wearing surfaces, a rotatable'chuck for receiving the drill steel shank and having driving means provided with wide elongated driving surfaces engaging the wearing surfaces on the polygonal shank portion for rotating the drill steel, means supported by said chuck and engaging said cylindrical rear end portion for centering and guiding the drill steel shank, and means rotatable with said chuck and cooperating with said intermediate reduced portion for locking the steel shank within said chuck, said polygonal shank portion cooperating with said centering and guiding means for limiting inward movement of the steel shank within said chuck.

4. In a rock drill chuck mechanism, the combination with a drill steel, of a rotatable chuck sleeve, a chuck bushing arranged within said chuck sleeve and adapted to receive the drill steel shank and having means adapted to lock the shank for rotation therewith, and a locking ring for connecting said chuck bushing to said chuck sleeve and for locking said steel shank within said chuck bushing.

5. In a rock drill chuck mechanism, the combination with a drill steel, of a rotatable chuck sleeve, a chuck bushing arranged within said chuck sleeve and adapted to receive the drill steel shank and having means adapted to lock the shank for rotation therewith, and a locking ring for connecting said chuck bushing to said chuck sleeve and for locking said steel shank within said chuck bushing, said chuck mechanism embodying means whereby said chuck bushing and said steel shank may be rotated with respect to the chuck sleeve and locking ring for releasing the steel shank from looking relation with said locking ring.

6. In a rock drill chuck mechanism, the combination of a drill steel having a shank, the rear end and intermediate portion of which are reduced in cross section and of less diameter than the steel body, said reduced portions bracketing an enlarged driving portion, and a chuck comprising a rotatable chuck sleeve, a wear bushing arranged within said chuck sleeve for receiving and guiding the reduced portion at the rear end of the steel shank, and a chuck bushing arranged within said chuck sleeve and adapted to receive the driving portion of the steel shank, and means for connecting said chuck bushing and chuck sleeve for rotation together.

7. In a rock drill chuck mechanism, the combination of a drill steel having a shank, the rear end and intermediate portion of which are reduced in cross section and of less diameter than the steel body, said reduced portions bracketing an enlarged driving portion, and a chuck comprising a rotatable chuck sleeve, a wear bushing arranged within said chuck sleeve for receiving and guiding the reduced portion at the rear end of the steel shank, and a chuck bushing arranged within said chuck sleeve and adapted to receive the driving portion of the steel shank, and means for connecting said chuck bushing and chuck sleeve for rotation together, said connecting means having embodied therein locking means for locking the driving portion of the steel shank within the chuck bushing, said locking means having locking portions projecting within said intermediate reduced portion.

8. In a rock drill chuck mechanism, the combination of a'drill steel having a shank, the rear end of which is reduced in cross section, and a chuck comprising a rotatable chuck sleeve; a wear bushing arranged within said chuck sleeve for receiving and guiding the reduced portion of the steel shank, and a chuck bushing arranged within said chuck sleeve and adapted to receive the driving portion of the steel shank, and means for connecting said chuck bushing and chuck sleeve for rotation together, said connecting means having embodied therein locking means for locking the driving portion of the steel shank within the chuck bushing, said chuck embodying means whereby said steel shank and said chuck bushing may be rotated with respecet to said chuck sleeve and locking means for releasing the driving portion of the steel shank from looking relation with said locking means.

9. In a rock drill chuck mechanism, the combination with a steel shank, of a rotatable chuck sleeve, a chuck bushing arranged within said chuck sleeve and having longitudinal keys engag-eable with longitudinal keyways within the chuck sleeve, said chuck bushing adapted to receive and support the drill steel shank, and means connected directly to said chuck sleeve by means distinct from said chuck bushing for locking said steel shank within said chuck bushing.

10. In a rock drill chuck mechanism, the combination with a steel shank, of a rotatable chuck sleeve, a chuck bushing arranged within said chuck sleeve and having longitudinal keys engageahle with longitudinal keyways within the chuck sleeve, said chuck bushing receiving and supporting the drill steel shank, and means-connected to said chuck sleeve for locking said steel shank within said chuck bushing, the chuck mechanism embodying means whereby said chuck bushing may be rotated relative to said locking means for locking the steel shank within said chuck bushing.

11. In a rock drill chuck mechanism, the combination with a steel shank, of a rotatable chuck sleeve, a chuck bushing arranged within said chuck sleeve and having longitudinal keys engageable with longitudinal keyways within the chuck sleeve, said chuck bushing adapted to receive and support the drill steel shank, and means connected to said chuck sleeve for locking said steel shank within said chuck bushing, said keyways in said chuck sleeve being laterally elongated to permit rotary motion of the steel shank and chuck bushing with respect to said chuck sleeve into released position with respect to said locking means.

12. In a rock drill chuck mechanism, the combination of a drill steel having a shank, the rear end of which is reduced in cross section, and a chuck comprising a rotatable chuck sleeve, a wear bushing arranged within said chuck sleeve for receiving and guiding the reduced portion of the steel shank, and a chuck bushing rotatably mounted within said chuck sleeve and adapted to receive and interlock with the driving portion of the steel shank, and means relative to which said chuck bushing is rotatable for connecting said chuck bushing and chuck sleeve forrotation together, said connecting means having embodied therein locking means for locking the driving portion of the steel shank within the chuck bushing and including means for limiting rotation of said chuck bushing relative to said sleeve and locking means.

13.- In a rock drill chuck mechanism, the combination of a steel shank of polygonal cross section, a rotatable chuck sleeve, a chuck bushing interlocked with said chuck sleeve for rotation therewith and having a polygonal socket for receiving the steel shank for interlocking the steel shank with the bushing, means for interlocking said'bushing with said sleeve permitting limited rotary motion of said bushing relative to said sleeve, and means connected to said chuck sleeve for locking said steel shank within said chuck bushing, said shank being rotatable with said bushing relative to said sleeve to effect locking of the shank by said locking means.

14. In a rock drill chuck mechanism, the combination of a steel shank of polygonal cross section, a rotatable chuck sleeve, a chuck bushing interlocked with said chuck sleeve for rotation therewith and having a polygonal socket for receiving the steel shank for interlocking the steel shank with the bushing, means for interlocking said bushing with said sleeve permitting limited r rotary motion of said bushing relative to said sleeve, and means connected to said chuck sleeve and said chuck bushing for locking said steel shank within said chuck bushing, said shank being rotatable with said bushing relative to said sleeve to effect locking of the shank by said looking means.

15. In a rock drill chuck mechanism, the combination with a steel shank, of a rotatable chuck sleeve, a chuck bushing arranged within said chucksleeve and having interlocking means engageable with means on the chuck sleeve, said chuck bushing adapted to receive and support the V drill steel shank, and means connected to said chuck sleeve for locking said steel shank within said chuck bushing, said interlocking means on said chuck sleeve and chuck bushing being formed to permit rotary motion of the steel shank and chuck bushing with respect to said chuck sleeve into locked or released position with respect to said locking means.

16. In a rock drill chuck mechanism, the combination with a steel shank, of a rotatable chuck sleeve, and a chuck bushing arranged within said chuck sleeve and having longitudinal keys engageable with longitudinal keyways within the chuck sleeve, said chuck bushing adapted to receive and support the drill steel shank, means for locking said steel shank within said chuck bushing, said keyways in said chuck sleeve being laterally elongated to permit rotary motion of the steel shank and chuck bushing with respect to said chuck sleeve into released position with respect to said locking means.

17. In a rock drill chuck mechanism, the combination of a drill steel having a shank provided with a shank portion and a portion of reduced cross section connecting said shank portion with the steel body, a rotatable chuck for receiving the drill steel shank and having driving means provided with wide elongated driving surfaces engaging said elongated driving shank portion for rotating the drill steel, and means rotatable with said chuck and cooperating with said reduced portion for locking the steel shank within said chuck, the steel body in advance of said reduced portion engaging said locking means for limiting inward movement of the steel shank within said chuck.

18. In a drill steel chuck mechanism, the combination of a drill steel having a' shank provided with an enlarged driving portion of polygonal cross section and a cylindrical portion of reduced cross section connecting said driving portion with the steel body, said driving portion provided with wide elongated wear surfaces, a rotatable chuck for receiving the steel shank and having driving means formed with a polygonal socket for receiving the polygonal driving portion of said shank and provided with wide elongated driving surfaces cooperating with said wear surfaces on said driving portion for rotating the steel, and a looking member rotatable with said chuck and having a polygonal opening through which the polygonal driving portion of said shank is insertable, said shank and driving means being rotatable relative to said chuck and locking member for looking the polygonal driving shank portion within the chuck, said locking member surrounding the reduced portion of the drill steel shank and having locking portions projecting within said reduced shank portion when the drill steel shank is in locked position within said chuck.

ELMER G. GARTIN. 

